Generally, the amount of data used to represent video data is large. Accordingly, when transmitting video data from an apparatus storing the video data to some other apparatus, the video data may be encoded and compressed in order to reduce the amount of data to be transmitted.
Further, in a recent system, high-definition video data such as full High Vision video may be transmitted. When transmitting such high-definition video data, if the video data is encoded and compressed, the amount of data to be transmitted is still large, requiring a wide transmission bandwidth to transmit the video data. To address this, there have been proposed techniques for transmitting encoded and compressed video data over a plurality of communication paths or a plurality of communication channels (for example, refer to Japanese Laid-open Patent Publication Nos. H10-108175 and 2000-224230).
For example, in the image encoding/transmitting system disclosed in Japanese Laid-open Patent Publication No. H10-108175, the transmitter divides input video into a number, N, of simplified moving images, encodes the simplified moving images, and transmits the resulting simplified moving image codes over a plurality of different transmission channels, respectively. On the other hand, at the receiver, the received simplified moving image codes are decoded independently of each other by using a plurality of decoders, and the original video is reconstructed by combining the decoded simplified moving images or by interpolating between them. The N simplified moving images are generated, for example, by allocating the original video frames to the N simplified moving images in sequence. Alternatively, the N simplified moving images are generated by dividing each one of the original video frames into blocks of N pixels and by extracting pixels at specific positions from the respective blocks.
In the real time communication method disclosed in Japanese Laid-open Patent Publication No. 2000-224230, a plurality of communication paths are set up between a transmitting terminal and a receiving terminal, and information data that differ in importance are transmitted over the respective communication paths. For example, an information packet containing an I frame, an information packet containing a B frame, and an information packet containing a P frame are transmitted from the transmitting terminal to the receiving terminal over one communication path. On the other hand, the information packet containing the I frame is also transmitted from the transmitting terminal to the receiving terminal over the other communication path.